468 Scientific Proceedings, Royal Dublin Society. 



obtain seeds of the Rose Bay (Epilobium angustifolitim, Linn.), although it is 

 so commonly grown in gardens. 



It will therefore be seen that it was not always possible to obtain seeds 

 for experiment that were ripened in the preceding season. In every case 

 I have given (in brackets), as far as known, the year in which the seeds were 

 ripened. In a few cases the age was uncertain, as the packets were not dated 

 at the time of collection, these having been collected as specimens of the seed 

 and not with a view to germination. In very few instances, however, were 

 the seeds more than five years old. 



The number of seeds of each species experimented on varied greatly, 

 depending on the number of seeds in my possession and the diflSculty of 

 obtaining them. Wliere the seeds were counted the number sown usually 

 varied between five and fifty. In one case as few as two were sown and in 

 another as many as 250. In many cases, however, where the seeds were 

 small or abundant tlie number was not counted. It may safely be assumed 

 in such eases that the number of seeds sown at least exceeded ten. 



The date of sowing the seed and the date of germination (where this 

 occurred) are given in eacli case. By germination is meant that the young 

 plant had actually appeared above ground or that the cotyledons were fully 

 expanded. The time required for germination depended largely on the 

 time of year at which the seeds were sown and on the species under 

 consideration, varying from one or two weeks to a year and a half. 



In some cases seedlings of various species were found growing wild in 

 their natural surroundings. The date of germination of such self-sown 

 plants is given. In the absence, however, of definite information relative 

 to the time of ripening of the seeds we can ouly measure within rough limits 

 the actual time during which they have been lying in the soil. Indeed in 

 some cases it is safe to assume that not one but two seasons intervened between 

 the time of their ripening and germination. 



In the majority of cases, the seeds were sown in flower-pots in the open 

 air. During the summer months, in order to lesson the work of watering 

 them, they were sunk in the soil almost up to the rim of the pot. In a 

 considerable number of instances, however, the seeds were sown in the open 

 ground. A better supply of moisture is maintained in the latter case, but 

 it is difiicult to be certain of the actual limits within which the seeds were 

 sown and, if the label happen to become displaced, impossible. 



In a very considerable number of cases the seeds failed to germinate 

 within the period of observation. Doubtless, if some of them had been given 

 longer time, they would probably have germinated. But in other cases, such 

 as that of oak, the seeds were dug up at the end of the time of observation 



